Active PTK6 appeared to correlate with grade of tumor; in low-grade ductal carcinomas, the P-Y342 signal was low to undetectable, but in the high-grade invasive ductal carcinomas, a strong P-Y342 PTK6 signal was detected at the membrane of tumors cells that had breached the basement membrane (Fig 3). The gene discussed is PTK6; the disease is invasive ductal breast carcinoma.